Thermally-responsive switch



INVENTOR ATTORNEYS W. E. LAGANKE Filed Sept.

THERMALLY RESPONS IVE SWITCH Jan. 13, 1931.

Patented Jan. 13, 1931 UNITED rSTATES 'WILBUR E. EAGANKE, 0F EAST CLEVELAND, OHIO THERMALLY-BESPONSIVE SWITCH Application tiled September 10, 1928. Serial No. 304,944.

This invention relates to switches of the type which are primarily, although not exclusively, intended for vuse in connection with panels.

An object of the invention is to provide a single blade thermally-controlled switch and, additionally, in such type of switch to provide a construction wherein the switch may be reset by moving the handle portion o of the switch once into the ofi' position which will reset the switch so that it may again be moved to the on position to reestablish the circuit which has previously been broken.

A further object of the invention is to provide a construction in which the operating handle of the switch carries the movable blade and a thermal element.

An additional feature of construction resides in providing a protecting covering for the thermal element so that it will not be moved to release the movable blade of the switch due to mechanical vibration or other similar causes.

Other objects of the invention will appear as the description proceeds.

Reference should be had to the accomy panying drawings forming a part of this Fig. 6 is a detall partial cross section of the thermal element.

The body of the switch is represented at 1 and is provided with a projecting handle 2 which may be grasped in order to operate the switch. The body of the switch is mounted upon a body of insulating material indicated at 3, the pivotal mounting for the switch being upon the pin or similar device which is represented at 4.

Projecting downwardly from the body is an extension 5 which is pivotally connected wlth a` member 6 which has spaced apart legs 7. These legs span a stationary pin 8 which is secured in the mountin 3. Surrounding the member 6 is a spring 9, one end of which seats against the pin 8 and the opposlte end of the spring bears against an enlarged head carried by the member 6. The construction which is just described is for the purpose of causing the switch to be thrown quickly to a full open or full closed position as the handle 2 is operated. It is believed that the operation and function of the device which has just been described will be. readily understood.

Fixedly mounted upon the body portion 1 is an arm 10 which is of conducting material. This arm at its lower end is provided with a face 11 which is adapted to contact with a conductingl member 12. Therefore, the face 11 may be designated as the blade of the switch. In order to prevent arcing between the blade of the switch and the member 12 with which it -cooperates there is provided a pivoted member 13, which member is pivoted directly upon the arm 10. This member 13 carries a roller 14, and a spring 15 is attached to the member 13 andA also to the 'body portion 1 of the switch. The function of the spring 15 is to normally urge the roller 14 into contact with the conductor or bus bar 12, particularly when the switch is being moved from open to closed position.` The rolling Contact between the bus bar 12 and the roller 14 will reduce any arcing to a minimum, and, of course, it is apparent that the electrical connection is established as soon as the roller 14 comes in contact with the bus bar 12. The position of the switch in the initial engagement between the roller and the bus bar 12- is indicated in dotted lines in Fig. 2. Upon the complete closing movement of the switch member the face 11 establishes contact with the bus bar 12 and this contact is maintained'due to the action of the spring 9. When contact between face 11 vand bus bar 12 is bein broken, the roller 14 remains in contact wlth the bus bar 12 until the spring 9 has com ressed over their-enter, thereupon the roller reaks away from the bus bar with a snap.

The body portion 1 of the switch 1s made of non-conducting material and, as before explained, the member 10 is pivotally mounted thereon by the pivot screw 16. The pivot member 4 forms a terminal to which the end ofa fixed conductor 17 is attached, and connect-ing the pivot 16 and the pivot 4 is a U-shaped member 18. This U-shaped member may be compared to a hairpin and the looped portion thereof straddles a pin 19 which is mounted u on an insulated portion 22 at the lower en of the member -10. It will, therefore, be. apparent that the pin 19 is insulated with respect to the conducting portion 10. Current from bus bar 12 will pass through the pivoted arm 10 to the pivotal point 16, then traverse the U-shaped member 18 to the pivotal oint 4,' thence to the conductor 17. The ibregoing being true when the switch is in its closed position.

The U-shaped member 18 is made of s ecial metal so that when the current passmg through the same exceeds a predetermined amount it will cause the member 18. to

. buckle and the looped end thereof will be caused to bow outwardly, thereby lifting itself away from contact with the pin 19. As soon as this takes place the member 10, which is pivoted to the body portion 1 is free to move about its pivot under the action of the spring 15, thus removing the contact face 11 from engagement with the bus bar 12 and so breaking the circuit. The po- 4sition of the switch members just described is clearly illustrated in Fig. 3 of the drawings.

The pin 19 is formed with a bevelled forward face, as indicated at 19 in Fig. 3. In order to reestablish the engagement .of the member 18 with the pin/19, it is only necessary to move the handle 2 into the position reversed from that shown in F ig. 3. that is to say to move the handle 2 normally to the oli' posit-ion. This will cause the member 18 to be moved toward the right (referring to Fig. 3), and at the same time the mel'nber l0 will move somewhat until the rear end thereof engages with the stop 20. Due to the bevelled surface of the pin 19 the rear leg of the U-shaped member 18 would cam over the pin 19. thus restoring the engagement between the member 18 and the pin 19. Thereupon the switch may be moved as to bring the cont-act face 11 into engagement with the bus bar 12 to reestablish the circuit through the switch.

In order to protect the member 18 and to prevent vibratory movement thereof causing the lower end to be released from the pin 19, the cover 21 of insulated material is attached to the body portion 1, preferably at' the points of the members 4 and 16, and the cover member 21 is caused to extend downwardly over the member 18 t\ a sufficient extent to accomplish its desired purpose, but obviously does not extend to completely cover the member 18 nor to interfere with its intended operation as before described.

' From the foregoing description. it will be.

ally mounted upon the said body portion, a'

thermally responsive conducting member mounted upon the said body portion and adjacent the movable contact member, means forming anV effective connection between the thermally responsive member and the blade member which connection is released when the thermally responsive member becomes heated to a predetermined amount, and a resilient member cooperating with the movable contact member and moving the said member away from the fixed contact member when the thermally responsive member becomes disengaged.

2. A thermally-controlled electric switch comprising a base member, a stationary contact member mounted thereon, an insulated body portion pivotally mounted upon the base, a movable contact member pivotally mounted upon the said body portion, a thermally responsive member which is electrically in. series with the said movable contact member, which thermally responsive member is'mounted upon the body portion, inter-engaging means carried by the thermallyl responsive member and the movable contact member whereby they normally move together, the said inter-engaging means being released when the thermally responsive member becomes heated to a predetermined amount, and means for causing the movable contact member to move about its pivot when released from engagement by the thermal responsive member.

3. A thermally-controlled electric switch comprising a base member, a stationary o' '1- tact member mounted thereon, an insulated body portion pivotally mounted upon the base, a movable contact member pivotally mounted upon the body, a thermally responsive U-shaped member which extends adjace the movable contact member, a in carried by the said movable contact mem er and adapted to be engaged by the U-shaped thermally responsive member whereby the ktwo said members normally move together,

the said thermally responsive member'becoming disengaged from said pin when the thermally responsive member is heated to a predetermined amount, and means for movingthe movable contact member with respect to the said thermally responsive member when the aforesaid disengagement takes place.

4. In a thermally-controlled electric switch comprising a base member, a stationary contact member mounted thereon, an insulated body portion pivo'tally mounted upon the base, a movable contact member pivotally mounted upon the said body portion, means for holding the said movable contact member in a definite relation with respect to the said body portion, said means comprising a thermally responsive conducting member which is in circuit wlth the lmovable contact member, the said thermally responsive member and the movable contact member having inter-engaging means which are adapted to be released when the thermally responsive member becomes heated to v a predetermined amount, means for moving the said movable contact member when said disengagement takes place, a stop carried by the base with which -the movable contact member engages when the Switch is moved to of position, the said thermally responsive member and said movable contact member being restored to inter-en aging position when the body portion o the switch is moved to off position.

5. A thermally-controlled switch comprising a base member, a stationary contact member mounted thereon, an insulated body portion pivotally mounted upon the base, a movable contact member pivotally mounted -upon the said body portion, a U-shaped thermally responsive conducting member which is mounted upon the said body portion and in circuit with a movable contact member, a pin carried by the said contact member which is normally elwaged within the U- shaped membei whereby the thermally responsive member and the movable contact member move as a unit, the said thermally responsive member disengaging the said pin when the thermally responsive member is heated to a predetermined degree, means for moving the movable contact member with respect to the thermally res onsive member when said disengagement ta es place, a stop with which the said movable contact member is ada )ted to engage whelt moved to olf position, tile said )in bein r )rovided with a cam surface whereby the Lts aped member cams over the end of the said pin to restore the connection between the movable contact member and the thermally responsive member when the body portion is moved to off y position. v

6. An electric switch comprising a base whereby the said members normall member, a stationary contact member mounted thereon, an insulated body portion pivotally mounted upon the base, a movable con- 'tact member carried by the said body portion and having a part adapted to engage with the fixed Contact member, a carrier pivotally mounted upon the movable contact member, a roller mounted in the said carrier and adapted to make a contact with the ixed contact member upon the initial closing of the switch, and resilient means cooperating with said carrier to properly osition the said roller with respect to the xed contact with the fixed contact member in advance of the final contact between the movable contact member and the fixed contact member when the switch is moved to its closed position. e

8. A thermally-controlled electric switch comprisin a base member, a stationary contact mem r mounted thereon, an insulated body portion pivotally mounted upon the base, a movable contact member pivotally mounted upon the said body portion, a thermally responsive conducting member mounted upon the body portion and in circuit with the movable Contact member, inter-engaging means between the thermally responsive member and the movable contact member move as a unit and become disengaged w en the thermally responsive member becomes heatsignature.

WILBUR E. LAGANKE. 

